An artfully shot, po-faced thriller about an American graduate student going to pieces on an extended break in Paris. Brady Corbet is excellent as thoroughly unlikable Simon, adrift in Paris's backstreet brothels, who strikes up a relationship with a sweet-natured prostitute (Mati Diop) that becomes in turn dependent and abusive. Producer Sean Durkin is part of the brain trust behind the critical hit Martha Marcy May Marlene, and Simon Killer shares that film's high points and pitfalls. It's just as beautiful and spooky, but it's also a bit dank, too studiously serious to maintain its thrills. The story, co-written by director Antonio Campos and his stars, meanders. Simon's gap year drops him into a chasm, but it's well before then, somewhere in the tangle of gloomy sex scenes and twisty subplots, that the character slipped from view.